Findings suggest public policy can't fix obesity

Oct. 2, 2011

Charles L. Baum

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Charles L. Baum

Gallup recently released a new poll, and the findings are nothing new: Most people are fat. Thanks to some new research, we know why. Or, more accurately, why not.

Many Americans currently hold a simplistic view of the reasons for their own weight gain. Very few people will own up to being their own worst enemy. Instead, they blame fast-food restaurants, the lack of grocery stores nearby or their busy lifestyle.

Although each of those may play a role, a new study I conducted with Lehigh University’s Shin-Yi Chou suggests it’s far more complicated than blaming your job, your neighborhood, or a specific business or industry.

Using data on body mass index (BMI) from two government data sets spanning a 27-year period, we analyzed multiple factors such as food prices, physical activity at work, restaurant prevalence, urbanization, employment and cigarette smoking to see if any could be attributed to the recent rise in obesity rates in America — and how much of that rise they were responsible for.

Based on the current conventional wisdom, many people might guess that food prices or restaurant prevalence would affect obesity the most. But the most significant factor influencing the rise in BMI among the variables we studied was the decline in cigarette smoking.

This makes sense: Cigarettes are an appetite inhibitor. But even this was an incredibly small factor, accounting for about2 percent of the rise in obesity.

Not surprisingly, the rise in BMI is also linked to urban sprawl: More driving equals less walking. Occupational fitness is another factor affecting weight: Less time sitting at a desk means more calories burned.

Neither of these dynamics, however, plays a large role. Urban sprawl accounts for only0.7 percent of the rise in BMI. Occupation fitness explains 0.5 percent. And fast-food prices, food-at-home prices and restaurant prevalence all registered statistically insignificant effects.

In other words, there are no one or two central “causes” of rising obesity.

The implications for public policy are substantial. Current proposals target just one obesity factor out of many in an often heavy-handed or punitive manner. For instance, Los Angeles recently placed a moratorium on new fast-food restaurants in certain areas of the city. Many states have considered a tax on sugar-sweetened beverages to decrease consumption of these drinks. Others call for subsidies to decrease the price of vegetables or tax breaks to encourage the spread of grocery stores in underserved areas.

Based on our research, it seems that these policies wouldn’t affect obesity rates in a significant way because the underlying factors they address are such small contributors to the rise in obesity rates.

One option then is to battle obesity by tackling each of its many factors, in a kind of death-by-a-thousand-cuts strategy. But public policy is a blunt instrument, too ham-handed to pullit off. There are simply toomany factors and individual choices.

The solution is instilling personal responsibility.

People gain weight when they consume more calories than they burn off. And many differentlifestyle decisions can lead to weight gain, just as there are many different approaches to weight loss.

No public-policy regimen can effectively target obesity unless it literally punishes people for being fat. And who wants to weigh himself or herself at the nearest IRS branch office?

The best policy is to educate people about nutrition and how the calorie equation works. Whether or not they use this knowledge to benefit their health is ultimately up to them.

Charles L. Baum is a professor of economics at Middle Tennessee State University.